Thrust Characterization of a T 6 Hollow Cathode IEPC-2005-257

Using a target-based measurement system, the thrust produced by a T6 ion engine hollow cathode has been measured, with neon, argon, krypton and xenon as propellants, for discharge current values of 5-25 A, a wide range of mass flow rates and two different orifice diameters. The calculated values of specific impulse, which are higher for lower atomic masses, are generally in excess of those that could be attributed to heating a gas to thermal equilibrium with the walls. This seems to suggest, as a first hypothesis, an arcjetlike operation mechanism. Nomenclature b = beam width D = target diameter e = electron charge E = Young’s modulus F = thrust g = acceleration of gravity at sea level h = beam thickness Isp = specific impulse k = Boltzmann constant L = beam length m = atomic mass m& = mass flow rate P = optical path length T = heavy-particle temperature Δθ = angular deflection Δx = linear displacement * PhD Candidate, Astronautics Research Group, School of Engineering Sciences, pg4@soton.ac.uk. † Professor, Astronautics Research Group, School of Engineering Sciences, sbg2@soton.ac.uk. ‡ Sole Proprietor, dg.fearn@virgin.net.